Yes, the battle pass will not be able to be purchased with V-Bucks for season 3, meaning you will just have to make a payment with your method of payment similar to purchasing the PVE content or when you actually buy Vbucks. They just allowed the Battle Pass to be purchasable with Vbucks for season 1 as a bit of an introduction to the system to people who may have stocked up on Vbucks and may have felt a bit shafted, or have earned a lot of Vbucks through PVE and wanted to try the system out.

Please provide proof of this claim. You say this, but I cannot find any evidence of an Epic employee stating that.